Both of these were stock spam, and both of these spam messages passed their respective SPF checks, meaning that they both did, indeed, come from Google's servers. Looks like Google may not be as invincible as I once thought.

Perhaps that explains why my shares in the company have been flat for three months.

With Google’s Abuse department being nonexistant and/ or unwilling to deal with complaints, I’m surprised that they haven’t been a much abused target before this. (I’m getting them as well)

Especially since emails sent through the GMail service do not report where the message originated from before reaching GMail’s boxes when sent by a GMail user. (Or at least they didn’t last time I checked.)